ANTI-ANNEXIN V LEVELS AND HAEMATOLOGICAL INDICES IN SICKLE CELL ANAEMIA PATIENTS IN VASOOCLUSIVE CRISIS AT LAGOS UNIVERSITY TEACHING HOSPITAL

Abstract

Background: Annexin V is a glycoprotein with anticoagulant activity. IgG and IgM Anti
AnnexinV antibodies have the ability to displace annexin V from phospholipid surfaces and
this has been linked with enhanced prothrombotic conditions such as vasoocclusive crisis, the
hallmark of SCA. Anti-annexin V antibodies have been strongly associated with VOC. The
association of Anti-Annexin V antibodies and the extent of its rise in VOC is yet to be fully
determined in Nigerians suffering from SCA.
Objectives: To determine the levels of IgM and IgG antibodies to Annexin V in SCA in crisis and steady states in order to assess contribution of the procoagulant effect of AntiAnnexin V to vasoocclusive crisis and its severity. Materials and Methods: This is a cross sectional case control study. The study comprises of
SCA subjects; 35 subjects in vasoocclusive crisis, 35 subjects in steady states and 20 HbAA
control subjects. Anti-annexin V antibodies activity was determined with ELISA KIT (Lot
number: 1604700. DEMEDITEC). Haematological parameters were analysed using
Haematology autoanalyser (COATRONM2, SYSMEX).
Results: The results showed that the prevalence of IgG anti-annexinV seropositivity was
found to be 22.9% in crisis, 20.0% in steady state and 0.0% in controls. The seropositivity
of IgM anti-annexin V was significantly higher in steady state than in control (p = 0.015),
but in VOC the seropositivity of anti annexin V IgM, though higher than in controls was not
statistically significant (p=0.071).The mean platelet count in the study subjects were
287.8±125.1x109cells/L,288.4±132.6x109cells/L and 179.5±56.4 x109cells/L, the difference
in mean platelet count was significantly lower in the control subjects than in the SCA
groups (p= 0.002).
Conclusion: Serum levels of IgM and IgG anti-annexin V do not significantly differ
between steady state and VOC. There is positive and significant correlation between the
platelet count and IgM anti-annexin V in patients with SCA in steady state.

ANTI-ANNEXIN V LEVELS AND HAEMATOLOGICAL INDICES IN SICKLE CELL ANAEMIA PATIENTS IN VASOOCLUSIVE CRISIS AT LAGOS UNIVERSITY TEACHING HOSPITAL